1. Field of the Invention
The present invention relates to a ceramic member and a manufacturing method for the same.
2. Description of the Related Art
A ceramic member such as a heater or an electrostatic chuck is used in a conventional semiconductor manufacturing apparatus or liquid crystal manufacturing apparatus. These ceramic members are ceramics, in which a metallic member such as an electrode or a resistance heating element is buried. Such a ceramic member is generally formed by aluminum nitride, alumina, or the like having high heat resistance and high corrosion resistance.
Moreover, forming an anticorrosion member used under a corrosive gas environment by high corrosion resistant yttria has been proposed (Japanese Patent Application Laid-open Nos. 2002-68838 and 2002-255647). Furthermore, an anticorrosion member having an yttria film formed on an alumina surface by plasma spraying has been proposed (Japanese Patent Application Laid-open No. 2001-31484).
In recent years, however, a ceramic member such as an electrostatic chuck or a heater has been required a higher corrosion resistance than usual. For example, since in-situ cleaning has been introduced to an etching process, the ceramic member is exposed to a stricter halogen corrosive gas plasma environment. Therefore, even with a ceramic member made of aluminum nitride or alumina, avoiding corrosion may be impossible.
In order to solve the problem described above, applying the higher corrosion resistant yttria to a ceramic member is attempted. However, new problems described below have occurred. Yttria has poor mechanical strength such as bending strength or fracture toughness. Therefore, when malting a ceramic member of yttria, it may break during a manufacturing process, and yields may thus decrease. Cracks or chipping may occur while processing for making a hole in which a terminal joined with a metallic member such as an electrode or a resistance heating element will be inserted. In addition, when brazing the terminal to the metallic member, it may break due to thermal stress.
Meanwhile, a yttria film formed by plasma spraying may be applied to a ceramic member. However, since the yttria film formed by plasma spraying is porous, corrosion resistance is insufficient, and particle generation cannot be prevented. Moreover, high volume resistivity required for using as a dielectric layer of an electrostatic chuck cannot be provided.